Optically clear plastics that demonstrate confined crystallization are useful for various applications including holographic data storage. Materials which exhibit the ability to undergo a threshold phase change and concomitant change in refractive index have been reported as a potential method to read and write holograms in a suitable storage media. However, a commercially viable material has yet to be discovered. Accordingly, there is a need for improved materials which exhibit confined crystallization and are easily processed, through which enhanced holographic data storage applications can be achieved.